/Engine/Plugins/Media/MediaPlate/Source/MediaPlateEditor/Public/MediaPlateEditorModule.h
Call this if you want to check if your media source is a drag and drop media source. If it is, then this will remove it from this module and you can then change the outer (as it will be transient.)
True if it is a drag and drop media source.
bool RemoveMediaSourceFromDragDropCache ( [UMediaSource](API\Runtime\MediaAssets\UMediaSource) * MediaSource )